A key requirement for a valid clinical investigation is the accurate and consistent collection of subject data. Such data can include objective measurements, such as vital signs and body weight, as well as subjective patient assessments, such as a felt level of pain and emotional state. In the past, this data was gathered via paper reports (such as a “questionnaire” or a “diary”), which users (subjects and/or clinicians) would complete according to a particular schedule, often spanning a period of weeks, months, or even years. The content of each report typically consists of a series of “items” consisting of a “stem” statement, instruction, or question and structured response options pertaining to the item. Items might ask the user to enter information concerning presence and/or severity and/or duration of symptoms (e.g., nausea, headache), behaviors (e.g., took a pill, vomited, fell asleep), attitudes and emotions (e.g., anger, sadness), or other sorts of health-related information, including text or narrative.
A typical clinical investigation is planned via a “protocol” to occur as a sequence of “epochs” (often referred to as “study phases”), each specifying the treatments or activities to be undertaken during that period. Typically the collection of certain data will be scheduled to occur in one or more of these epochs such that the configuration of the data to be captured will change during the conduct of the investigation. For example, the protocol may specify that the content of a morning report change after a week has elapsed so that new questions can be posed (e.g., “Are you now taking the blue pills instead of the ones you took last week? If so, how many did you take?”). Such a change in planned content is quite common when the epoch changes. However, such changes can occur within a given epoch as well.
In order to restrict users' ability to enter their measurements and assessments to the schedule required by the clinical protocol, and to facilitate the accurate retrieval of patient data, paper reports have been replaced with electronic data loggers, often in the form of portable handheld electronic devices. An example of an electronic data logger is described in U.S. Pat. No. 5,778,882, the contents of which are incorporated herein in their entirety. Such systems only permit users to enter the required data during a time window specifically scheduled for capturing that data, which helps ensure that the data collected is valid. For example, after a subject has completed a daily data report for Monday morning, an electronic reporting device might not permit the patient to access the patient data entry screen or enter any more data for Monday, thus avoiding duplicate reports or contradicting values. Then on Tuesday morning, 24 hours after the Monday report first had become available, an opportunity for completing the new report scheduled for Tuesday morning would be made available to the subject.
There are many ways of defining a schedule for the collection of data in a clinical trial and for specifying the various conditions that need to be met in order to request and collect data. In many trials, the schedules are complex and involve conditional branching. Furthermore, trials can span long periods of time that last for many months or even years. While such complexity is helpful for enforcing conformance with the schedule for planned entry of patient data, difficulties can arise in training users in the use of electronic data logging devices that have such schedules, as well as in the development and testing of such content or the devices or systems for presenting information according to contingent scheduling.
For both training and testing, the challenge is to explore all options that can be provided by the data logging application while ensuring that the behavior of the application is not compromised in the process.